1. Field of the Background
The invention relates to a process for preparing a latex based on polypyrrole, from which it is possible to obtain adherent homogeneous films in a wide range of thickness and having high conductivity.
2. Discussion of the Background
It has already been proposed, in British Patent Application 2,181,367, to prepare conducting films based on pyrrole by polymerizing pyrrole in an aqueous medium in the presence of a polyvinyl alcohol and a substance capable of providing the property of conductivity, such as a ferric compound or a persulphate.
Similarly, it has been proposed--in the document Journal of Colloid and Interface Science, Vol. 118, No. 2, August 1987, p. 410-416--to prepare a water-stable latex based on polypyrrole by employing a technique of polymerization of pyrrole involving ferric chloride as an initiator and a partially hydrolized polyvinyl acetate as a stabiliser.
However, these processes lead to polymers having low conductivity. The films obtained with these polymers are, in general, poorly homogeneous or adhere only weakly to metals, glasses and metallized glasses.